Process and apparatus for treating a heavy hydrocarbon feedstock

ABSTRACT

An apparatus and process for treating a heavy hydrocarbon feedstock having a specific gravity differential between components of the feedstock is disclosed. The apparatus includes a treatment vessel having an inlet for receiving the feedstock. The apparatus also includes a primary separation container located in the treatment vessel, the primary separation container being operable to accumulate feedstock to cause a low specific gravity portion of the feedstock to separate and rise to an upper surface of the accumulated feedstock. The apparatus also includes a first weir for collecting the low specific gravity portion from the surface of the accumulated feedstock in the primary separation container. The apparatus further includes a first outlet in the primary separation container, the first outlet being operably configured to receive settling solids in the accumulated feedstock and to produce a first discharge stream at the first outlet. The apparatus also includes a secondary separation container located in the treatment vessel to receive the collected low specific gravity portion, the secondary separation container being operable to accumulate the collected low specific gravity portion to cause hydrocarbon products to separate and rise to an upper surface of the accumulated low specific gravity portion of the feedstock. The apparatus further includes a product outlet for collecting the hydrocarbon products from the upper surface of the accumulated low specific gravity portion to produce a hydrocarbon product stream at the product outlet.

BACKGROUND

1. Field of Invention

This invention relates generally to hydrocarbon extraction and moreparticularly to a process and apparatus for treating a heavy hydrocarbonfeedstock having a specific gravity differential between components ofthe feedstock.

2. Description of Related Art

Heavy hydrocarbon feedstocks are generally viscous and may be entrainedwith other components such as rock, sand, clay, and other minerals. As aresult, heavy hydrocarbons require processing to separate usefulhydrocarbon products from residue before transport and refining.

One example of a heavy hydrocarbon ore deposit is the Northern Albertaoil sands, which comprises about 70 to about 90 percent by weight ofmineral solids including sand and clay, about 1 to about 10 percent byweight of water, and a bitumen or oil film. The bitumen may be presentin amounts ranging from a trace amount up to as much as 20 percent byweight. Due to the highly viscous nature of bitumen, when excavated someof the ore may remain as clumps of oversize ore, requiring sizing toproduce a sized ore feed suitable for processing. The ore may also befrozen due to the northerly geographic location of many oil sandsdeposits, making sizing of the ore more difficult. The sized ore feed istypically processed by adding water to form a slurry in a locationproximate to the ore deposit, and the resulting slurry ishydro-transported through a pipeline to a processing plant forseparation of the hydrocarbon products from the sand and other minerals.

Low specific gravity hydrocarbons may be separated from sand and water,which generally have higher specific gravity, by accumulating thefeedstock in a separation vessel and allowing gravity separation tooccur. Such a separation vessel may have a large diameter relative toside wall height and may include a conical bottom for sand removal. Foradequate separation of hydrocarbons, the relatively quiescent conditionsof the accumulated feedstock may be required in the vessel, which hasthe adverse effect of allowing neutral density asphaltene mats toaccumulate at an interface between the separated hydrocarbon productsand the water. These asphaltene mats accumulate as rag layers and may bedifficult to remove.

There remains a need for improved processes and apparatus for treatingheavy hydrocarbon feedstocks.

SUMMARY

In accordance with one aspect of the invention there is provided anapparatus for treating a heavy hydrocarbon feedstock having a specificgravity differential between components of the feedstock. The apparatusincludes a treatment vessel having an inlet for receiving the feedstock.The apparatus also includes a primary separation container located inthe treatment vessel, the primary separation container being operable toaccumulate feedstock to cause a low specific gravity portion of thefeedstock to separate and rise to an upper surface of the accumulatedfeedstock. The apparatus also includes a first weir for collecting thelow specific gravity portion from the surface of the accumulatedfeedstock in the primary separation container. The apparatus furtherincludes a first outlet in the primary separation container, the firstoutlet being operably configured to receive settling solids in theaccumulated feedstock and to produce a first discharge stream at thefirst outlet. The apparatus also includes a secondary separationcontainer located in the treatment vessel to receive the collected lowspecific gravity portion, the secondary separation container beingoperable to accumulate the collected low specific gravity portion tocause hydrocarbon products to separate and rise to an upper surface ofthe accumulated low specific gravity portion of the feedstock. Theapparatus further includes a product outlet for collecting thehydrocarbon products from the upper surface of the accumulated lowspecific gravity portion to produce a hydrocarbon product stream at theproduct outlet.

The apparatus may include a feed manifold operably configured to receivea flow of feedstock from the inlet and cause the feedstock to flow alongthe feed manifold to the primary separation container for conditioningthe feedstock flow to facilitate separation of the low specific gravityportion in the primary separation container.

The feed manifold may include a plurality of adjacently located openchannels extending between the inlet and the primary separationcontainer, the open channels being operable to reduce turbulenceintensity in the feedstock flow.

The feed manifold may be operably configured to cause a feedstock flowinto the primary separation container having a Reynolds Number of about20,000.

The primary separation container may include a downwardly inclined baseoperably configured to direct settling solids in the accumulatedfeedstock toward the first outlet of the treatment vessel.

The downwardly inclined base defines a first portion of the primaryseparation container and the primary separation container may furtherinclude a second portion of the primary separation container located toreceive the solids from the downwardly inclined base, the first outletbeing located at a low point in the second portion of the primaryseparation container.

The secondary separation container may be located generally below thedownwardly inclined base of the primary separation container.

The first weir may include a catchment located behind the weir, thecatchment being operable to receive the collected low specific gravityportion and to direct the collected low specific gravity portion to thesecondary separation container.

The apparatus may include a conduit extending between the catchment andthe secondary separation container.

The first weir may include a weir having a J-shaped cross section.

The first weir may include a serpentine weir.

The first weir may be positioned to collect the low specific gravityportion from a first area of the upper surface of the accumulatedfeedstock in the primary separation container, and the apparatus mayfurther include a second weir positioned proximate a second area of theupper surface of the accumulated feedstock in the primary separationcontainer, the second weir being operable to permit feedstock in thesecond area from which a substantial portion of the low specific gravityportion has been collected to overflow to produce a second dischargestream at a second outlet.

The apparatus may include a first launder box located to receive andaccumulate overflowing feedstock from the second weir and the secondoutlet may be located at a low point in the first launder box.

The second discharge stream may include at least water and a fine solidscomponent.

The first discharge stream may include at least water and a coarsesolids component.

The first discharge stream may further include asphaltenes.

The apparatus may include a third outlet located in the secondaryseparation container of the treatment vessel, the third outlet beinglocated at a low point in the secondary separation container forproducing a third discharge stream at the third outlet.

The third outlet may include a water boot disposed below the secondaryseparation container, the water boot having an outlet for dischargingthe third discharge stream.

The product outlet may include a third weir located in the secondaryseparation container to cause the hydrocarbon products in theaccumulated low specific gravity portion to overflow to produce thehydrocarbon stream at the product outlet.

The product outlet may include a second launder box located to receiveand accumulate the overflowing low specific gravity portion from thethird weir and the product outlet may be located at a low point in thesecond launder box.

The feedstock may include an added diluent and the hydrocarbon productmay include a hydrocarbon product portion and a diluent portion.

The added diluent may include one of a paraffinic diluent and anaphthenic diluent.

The feedstock may include at least about 60% diluent.

The treatment vessel may include a pressure containment vessel and mayfurther include at least one gas outlet operably configured to dischargegaseous products released from the feedstock during treatment.

The apparatus may include a regulator regulating an operating pressurein the treatment vessel.

The regulator may be operably configured to regulate the operationpressure by causing the at least one gas outlet to be activated torelease gaseous products when the operating pressure in the treatmentvessel is above a pre-determined maximum operating pressure, and byintroducing a supplementary pressurizing gas when the operating pressurein the treatment vessel falls below a pre-determined minimum operatingpressure.

In accordance with another aspect of the invention there is provided aprocess for treating a heavy hydrocarbon feedstock having a specificgravity differential between components of the feedstock. The processinvolves receiving the feedstock at an inlet of a treatment vessel, andaccumulating feedstock in a primary separation container in thetreatment vessel to cause a low specific gravity portion of thefeedstock to separate and rise to an upper surface of the accumulatedfeedstock. The process also involves collecting the low specific gravityportion from the surface of the accumulated feedstock in the primaryseparation container, and directing settling solids in the accumulatedfeedstock toward a first outlet of the treatment vessel to produce afirst discharge stream at the first outlet. The process further involvesaccumulating the collected low specific gravity portion in a secondaryseparation container in the treatment vessel to cause hydrocarbonproducts to separate and rise to an upper surface of the accumulated lowspecific gravity portion, and collecting the hydrocarbon products fromthe upper surface of the accumulated low specific gravity portion toproduce a hydrocarbon product stream at a product outlet.

Receiving the feedstock may involve receiving a flow of feedstock at theinlet and causing the feedstock to flow along a feed manifold betweenthe inlet and the primary separation container for conditioning thefeedstock flow to facilitate separation of the low specific gravityportion in the primary separation container.

Conditioning the feedstock flow may involve causing the feedstock toflow along a plurality of adjacently located open channels extendingbetween the inlet and the primary separation container, the openchannels being operable to reduce turbulence intensity in the feedstockflow.

Causing the feedstock to flow along the feed manifold may involvecausing a feedstock flow into the primary separation container having aReynolds Number of about 20,000, which is significantly higher than flowrates in conventional API separators.

Directing settling solids in the accumulated feedstock toward the firstoutlet of the treatment vessel may involve causing the solids to bedirected along a downwardly inclined base of the primary separationcontainer toward the first outlet.

The downwardly inclined base may define a first portion of the primaryseparation container and the method may further involve receiving thesettling solids in a second portion of the primary separation containerlocated to receive the solids from the downwardly inclined base, thefirst outlet being located at a low point in the second portion of theprimary separation container.

Accumulating the low specific gravity portion in the secondaryseparation container may involve accumulating the low specific gravityportion in a secondary separation container located generally below thedownwardly inclined base of the primary separation container.

Collecting the low specific gravity portion may involve overflowing thelow specific gravity portion at a first weir disposed to receive anoverflow stream from the primary separation container.

Collecting the low specific gravity portion may involve receiving thelow specific gravity portion overflowing the first weir in a catchmentlocated behind the weir and directing the collected low specific gravityportion to the secondary separation container.

Directing the collected low specific gravity portion to the secondaryseparation container may include causing the collected low specificgravity portion to flow through a conduit extending between thecatchment and the secondary separation container.

Receiving the low specific gravity portion at the first weir may involvereceiving the low specific gravity portion at a weir having a J-shapedcross section.

Receiving the low specific gravity portion at the first weir may involvereceiving the low specific gravity portion at a serpentine weir.

Collecting the low specific gravity portion may involve collecting thelow specific gravity portion from a first area of the upper surface ofthe accumulated feedstock and may further involve overflowing feedstockfrom a second area of the upper surface from which a substantial portionof the low specific gravity portion has been collected to produce asecond discharge stream at a second outlet of the treatment vessel.

Overflowing feedstock from the second area of the upper surface mayinvolve causing the feedstock to overflow into a first launder box, thesecond outlet being located at a low point in the first launder box.

Producing the second discharge stream may involve producing a seconddischarge stream including at least water and a fine solids component.

Producing the first discharge stream may involve producing a dischargestream including at least water and a coarse solids component.

Producing the first discharge stream may involve producing a dischargestream including asphaltenes.

The process may involve producing a third discharge stream at a thirdoutlet of the treatment vessel, the third outlet being located at a lowpoint of the secondary separation container.

Producing the third discharge stream at the third outlet may involvecausing aqueous components to be collected in a water boot disposedbelow the secondary separation container, the water boot having anoutlet for discharging the third discharge stream.

Collecting the hydrocarbon products may involve overflowing theaccumulated low specific gravity portion.

Overflowing the accumulated low specific gravity portion may involvecausing the hydrocarbon products in the low specific gravity portion ofthe feedstock to overflow into a second launder box, the product outletbeing located at a low point in the second launder box.

The feedstock may include an added diluent, and collecting thehydrocarbon products may involve collecting a hydrocarbon productportion and a diluent portion.

The added diluent may include one of a paraffinic diluent and anaphthenic diluent.

The feedstock may include at least about 60% diluent.

The treatment vessel may include a pressure containment vessel and themethod may further involve causing gaseous products released from thefeedstock during treatment to be discharged from the treatment vesselthrough at least one gas outlet.

The process may involve regulating an operating pressure in thetreatment vessel.

Regulating the operation pressure may involve causing the at least onegas outlet to be activated to release gaseous products when theoperating pressure in the treatment vessel may be above a pre-determinedmaximum operating pressure, and introducing a supplementary pressurizinggas when the operating pressure in the treatment vessel falls below apre-determined minimum operating pressure.

In accordance with another aspect of the invention there is provided anapparatus for treating a heavy hydrocarbon feedstock having a specificgravity differential between components of the feedstock. The apparatusincludes provisions for receiving the feedstock at an inlet of atreatment vessel, and provisions for accumulating feedstock in a primaryseparation container in the treatment vessel to cause a low specificgravity portion of the feedstock to separate and rise to an uppersurface of the accumulated feedstock. The apparatus also includesprovisions for collecting the low specific gravity portion from thesurface of the accumulated feedstock in the primary separationcontainer, and provisions for directing settling solids in theaccumulated feedstock toward a first outlet of the treatment vessel toproduce a first discharge stream at the first outlet. The apparatusfurther includes provisions for accumulating the collected low specificgravity portion in a secondary separation container in the treatmentvessel to cause hydrocarbon products to separate and rise to an uppersurface of the accumulated low specific gravity portion, and provisionsfor collecting the hydrocarbon products from the upper surface of theaccumulated low specific gravity portion to produce a hydrocarbonproduct stream at a product outlet.

Other aspects and features of the present invention will become apparentto those ordinarily skilled in the art upon review of the followingdescription of specific embodiments of the invention in conjunction withthe accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

In drawings which illustrate embodiments of the invention,

FIG. 1 is a partially cut-away perspective view of a treatment vesselapparatus in accordance with a first embodiment of the invention;

FIG. 2 is a cross sectional view of the treatment vessel taken along aline 2-2 in FIG. 1;

FIG. 3 is another cross sectional view of the treatment vessel takenalong a line 3-3 in FIG. 2; and

FIG. 4 is further cross sectional view of the treatment vessel takenalong a line 4-4 in FIG. 2.

DETAILED DESCRIPTION

Referring to FIG. 1, an apparatus for treating a heavy hydrocarbonfeedstock according to a first embodiment of the invention is showngenerally at 100. The apparatus 100 includes a treatment vessel 102having an inlet 104 for receiving the feedstock. The feedstock has aspecific gravity differential between components of the feedstock.

In this embodiment the treatment vessel 102 includes a cylindricalportion 106 having first and second dome-shaped end walls 108 and 110.The cylindrical section 104 may be fabricated from a carbon steel pipesection having a wall thickness of about 12 mm. In other embodimentswhere the feedstock is corrosive, the inside surfaces of the treatmentvessel 102 may be treated to resist corrosion or a corrosion resistantmetal may be used to fabricate the treatment vessel. In one embodimentthe treatment vessel 102 may have a length of about 20 meters and adiameter of about 7 meters. Advantageously, fabrication of the treatmentvessel 102 may occur at an off-site location, since the aspect ratio ofthe cylindrical section 104 would permit subsequent transport to theprocessing location. In contrast, many prior art conical bottomseparators must be fabricated on-site due to their large diameter.

The apparatus 100 also includes a primary separation container 112located in the treatment vessel 102. The treatment vessel 102 is shownin cross-section in FIG. 2. Referring to FIG. 2, the primary separationcontainer 112 is operable to accumulate feedstock to cause a lowspecific gravity portion of the feedstock to separate and rise to anupper surface 114 of the accumulated feedstock.

The primary separation container 112 also includes a first weir 116 anda catchment 117 located behind the first weir for collecting the lowspecific gravity portion from the surface of the accumulated feedstock.The primary separation container 112 further includes a first outlet 119operably configured to receive settling solids in the accumulatedfeedstock and to produce a first discharge stream at the first outlet.

The treatment vessel 102 further includes a secondary separationcontainer 118. The secondary separation container 118 is located toreceive the low specific gravity portion collected at the catchment 117.Referring back to FIG. 1, in the embodiment shown the primary separationcontainer 112 includes a conduit 120 having an inlet opening 122 in thecatchment 117 for receiving the collected low specific gravity portionand an outlet 124 for discharging the collected low specific gravityportion into the secondary separation container 118.

The secondary separation container 118 is operable to accumulate thecollected low specific gravity portion to cause hydrocarbon products toseparate and rise to an upper surface 126 of the accumulated lowspecific gravity portion of the feedstock.

Referring back to FIG. 2, the treatment vessel 102 further includes aproduct outlet 128 for collecting the hydrocarbon products from theupper surface 126 of the accumulated low specific gravity portion toproduce a hydrocarbon product stream at the product outlet. In thisembodiment the product outlet 128 is located in a second launder box 152defined by a third weir 150. The product outlet 128 is located at a lowpoint in the second launder box 152.

In this embodiment the treatment apparatus 102 includes a feed manifold130, which is operably configured to receive a flow of feedstock fromthe inlet 104 and to cause the feedstock to flow along the feed manifoldto the primary separation container 112. The feed manifold is operableto direct the feedstock flow to the primary separation container 112while conditioning the flow to facilitate separation of the low specificgravity portion in the primary separation container.

The apparatus 100 is shown in cross section in FIG. 3. Referring to FIG.3, the feed manifold 130 includes a plurality of baffles 132 forming aplurality of channels 134, which receive a flow of feedstock from theinlet 104 and channel the feedstock flow to the primary separationcontainer 112. In other embodiments, the feed manifold 130 may include aplurality of ridges for conditioning the feedstock flow (not shown) inplace of the baffles 132.

Referring back to FIG. 2, in this embodiment the primary separationcontainer 112 includes a downwardly inclined base 136 operablyconfigured to direct settling solids in the accumulated feedstock towardthe first outlet 118 of the treatment vessel 102. The downwardlyinclined base 136 also forms a dividing wall between the primaryseparation container 112 and the secondary separation container 118.

In the embodiment shown, the first weir 116 has a generally J-shapedcross section, which defines the catchment 117. In other embodimentsapparatus 100 may include a serpentine weir. Serpentine weirs haveincreased length in the path of the flow, which increases the flow ratecapacity of the weir.

The apparatus 100 also includes a second weir 142 positioned proximatethe end wall 108 and defining a first launder box 138 located to receiveand accumulate feedstock overflowing from the second weir 142. Thesecond weir 142 separates the first launder box 138 from the primaryseparation container 112. The apparatus 100 also includes a secondoutlet 146, which is located at a low point in the first launder box138.

The apparatus 100 also includes a third outlet 148 located at a lowpoint of the secondary separation container 118. In one embodiment thethird outlet 148 comprises a water boot.

In one embodiment the treatment vessel 102 is operably configured tooperate under a positive pressure, and the treatment vessel includes agas outlet 154, which is operable to discharge gaseous products releasedfrom the feedstock during treatment. In this embodiment, the gas outlet154 is in communication with first and second conduits 158 and 160through a regulator 156 for regulating operating pressure in thetreatment vessel 102, as described later.

A further cross section through the secondary separation container 112of the apparatus 100 is shown in cross section in FIG. 4. In FIG. 4, aportion of the downwardly inclined base 136 is shown, and the container118 extends from under the downwardly inclined base to the third weir150.

Operation

The operation of the treatment 102 is described in greater detail withreference to FIG. 1 and FIG. 2. Referring to FIG. 2, a flow of heavyhydrocarbon feedstock is received at the inlet 104 and directed to thefeed manifold 130. In general, the flow rate of the feedstock flow mayfluctuate over time.

In one embodiment the heavy hydrocarbon feedstock comprises heated andde-aerated bitumen froth. An exemplary bitumen froth may comprise about80% hydrocarbon products, about 15% water, and about 5% solids. Thesolids may include sand, minerals, and other fine solids. The bitumenfroth may also have an added diluent. For example, the diluent maycomprise napthatenic or paraffinic compounds, and may be present in aproportion of 60-80% of the feedstock. Advantageously, the configurationof the treatment vessel 102 provides relatively shallow accumulations inthe primary separation container 112 and the secondary separationcontainer 118, thus limiting the inventory of feedstock, and hencediluent, in the treatment vessel. Conventional diluents are generally ofmore value than the hydrocarbon products being extracted and thusminimizing the diluent volume required is desirable.

The feedstock components generally have a specific gravity differentialthat is sufficient to cause gravity separation under horizontal flowconditions through the primary separation container 112. The hydrocarboncomponents (including diluent, if added) will generally have a specificgravity of less than unity, while the sand and other minerals willgenerally have a specific gravity greater than unity. Fine solids, suchas silt, may be largely suspended in the water, which will have aspecific gravity of close to unity.

Referring to FIG. 3, the feedstock is separated into a plurality ofseparate flows by the baffles 132 into the open channels 134, whichspread out the feedstock flow to provide a uniform feed into the primaryseparation container 112. The open channels 134 operate to reduceturbulence intensity and prevent formation of eddy currents in thefeedstock flow, which would tend to disrupt or delay onset of gravityseparation. For efficient operation of the apparatus 100, the flow rateof the feedstock should be as high as possible, without generatingexcessive turbulence in the primary separation container 112. Currentsdue to turbulence may work against upward movement and separation of thelow specific gravity portion of the feedstock. In one exemplaryembodiment the feedstock flow into the primary separation vessel 112 hasa Reynolds number of about 20,000.

In embodiments where the feedstock includes a paraffinic diluent, thefeed manifold also conditions the stream by providing sufficient time topermit precipitation coalescence of asphaltenes to occur.

The feedstock entering the primary separation container 112 accumulatesto a level of the weir 116. In embodiments where the feedstock flow rateis very high, the weir 116 may be configured in a serpentine shape toincrease the flow volume over the lip into the catchment 117 forcontrolling accumulation level in the primary separation container 112.Advantageously, the first weir 116 controls the accumulation level offeedstock in the primary separation container 112, despite variations infeedstock flow rate at the inlet 104.

The lower specific gravity portion of the feedstock rises to the uppersurface 114 of the accumulated feedstock, while higher specific gravitysand and other minerals begin to settle out along the downwardlyinclined base 136. The base 136 also directs the solids along toward aportion 164 of the primary separation container 112. In embodimentswhere precipitation of asphaltenes occurs, precipitated asphaltenes arealso directed along the base toward the portion 164 of the primaryseparation container 112. A cylindrical portion 106 of the treatmentvessel provides a rounded base in the container portion 164, whichfurther aids in directing solids and asphaltenes towards the firstoutlet 119, thus producing a first discharge stream as a slurry ofpredominantly coarse solids, asphaltenes, and water. Advantageously, thedownwardly inclined base 136 also serves to slow down thecross-sectional flow rate of the feedstock proximate the first weir 116.

The first weir 116 collects a substantial portion of low specificgravity hydrocarbon products in the catchment 117. The collected lowspecific gravity portion is received at the inlet 122 of the conduit 120and directed to the secondary separation container 118. The collectedlow specific gravity portion may include some proportion of water, sincecomplete separation at the first weir 116 of hydrocarbon products fromwater is not practically achievable due to a under high flow rateregimen.

The first weir 116 thus collects a substantive portion of the lowspecific gravity portion of the feedstock from an area 140 between anend of the feed manifold 130 and the first weir 116. The first weir 116also presents a barrier to passage of the hydrocarbon products past theweir to an area 144 between the first weir 116 and the second weir 142.Accordingly, the feedstock portion overflows at the second weir 142 hasrelatively low hydrocarbon product content and the first launder box 138produces a second discharge stream that comprises predominantly waterand fine solids.

Advantageously, in this embodiment the primary separation container 112has a relatively shallow separation pool, which facilitates constructionof the secondary separation container 118 generally below the primaryseparation container.

The low specific gravity portion collected at the first weir 116 isconducted to the secondary separation container 118 and accumulates to alevel of the third weir 150. As described above, the collected lowspecific gravity portion comprises predominantly water and hydrocarbonproduct since a substantial portion of the solids and asphaltenes areremoved in the primary separation container 112. However, mixing in theprimary separation container due to residual turbulence and a relativelyshort retention time under high flow rates may cause the collected lowspecific gravity portion to include at least some proportion of water.The hydrocarbon products in the secondary separation container 118separate and rise to an upper surface 126 while aqueous components aredrawn off as a third discharge stream at the third outlet 148. The thirddischarge stream thus predominantly comprises water, although some sand,asphaltenes, and/or other hydrocarbon products may be entrained in thethird discharge stream.

As the collected low specific gravity portion continues to flow into thesecondary separation container 118, the hydrocarbon products willoverflow at the weir 150 into the second launder box 152, where thehydrocarbon products are discharged at the product outlet 128 as ahydrocarbon product stream. The hydrocarbon product stream may comprisea significant proportion of diluent, which may be recovered from theproduct stream for re-use.

As disclosed earlier, during operation of the apparatus 100, gaseousproducts may be released from the feedstock causing increased operatingpressure in the treatment vessel 102. High operating pressure may resultin damage to the treatment vessel while low operational pressure mayresult in the flashing of feedstock components. The pressure regulator156 and conduits 158 and 160 facilitate maintaining the operatingpressure of the treatment vessel 102 within a desired safe range. Theregulator 156 is in communication with a source of pressurized gas (notshown) through the first conduit 158, and when the operating pressure inthe treatment vessel falls below a pre-determined minimum operatingpressure the regulator opens to allow the pressurized gas to enter thevessel. The pressurized gas may be a relatively inert gas, such as, forexample, nitrogen. Alternatively, should the operating pressure riseabove a pre-determined maximum operating pressure, the regulator 156opens to vent gaseous products through the second conduit 160. Thesecond conduit may be in communication with a recovery system (notshown) for recovering useful gaseous products or for safe disposal ofthe gaseous products.

In one embodiment, two or more of apparatus 100 may be verticallystacked for treating the feedstock in stages, with interstage feedingoccurring via the force of gravity.

Advantageously, the flow path through the treatment vessel 102 is freeflowing through all stages and thus the possibility of accumulatingasphaltene mats, as described earlier, is limited by the relatively highflow rate through the vessel.

While specific embodiments of the invention have been described andillustrated, such embodiments should be considered illustrative of theinvention only and not as limiting the invention as construed inaccordance with the accompanying claims.

1. An apparatus for treating a heavy hydrocarbon feedstock having aspecific gravity differential between components of the feedstock, theapparatus comprising: a treatment vessel having an inlet for receivingthe feedstock; a primary separation container located in the treatmentvessel, the primary separation container being operable to accumulatefeedstock to cause a low specific gravity portion of the feedstock toseparate and rise to an upper surface of the accumulated feedstock; afirst weir for collecting the low specific gravity portion from thesurface of the accumulated feedstock in the primary separationcontainer; a first outlet in the primary separation container, the firstoutlet being operably configured to receive settling solids in theaccumulated feedstock and to produce a first discharge stream at thefirst outlet; a secondary separation container located in the treatmentvessel to receive the collected low specific gravity portion, thesecondary separation container being operable to accumulate thecollected low specific gravity portion to cause hydrocarbon products toseparate and rise to an upper surface of the accumulated low specificgravity portion of the feedstock; and a product outlet for collectinghydrocarbon products from the upper surface of the accumulated lowspecific gravity portion to produce a hydrocarbon product stream at theproduct outlet.
 2. The apparatus of claim 1 further comprising a feedmanifold operably configured to receive a flow of feedstock from theinlet and cause the feedstock to flow along the feed manifold to theprimary separation container for conditioning the feedstock flow tofacilitate separation of the low specific gravity portion in the primaryseparation container.
 3. The apparatus of claim 2 wherein the feedmanifold comprises a plurality of adjacently located open channelsextending between the inlet and the primary separation container, theopen channels being operable to reduce turbulence intensity in thefeedstock flow.
 4. The apparatus of claim 2 wherein the feed manifold isoperably configured to cause a feedstock flow into the primaryseparation container to have a Reynolds Number of about 20,000.
 5. Theapparatus of claim 1 wherein the primary separation container comprisesa downwardly inclined base operably configured to direct settling solidsin the accumulated feedstock toward the first outlet of the treatmentvessel.
 6. The apparatus of claim 5 wherein the downwardly inclined basedefines a first portion of the primary separation container and whereinthe primary separation container further comprises a second portion ofthe primary separation container located to receive the solids from thedownwardly inclined base, said first outlet being located at a low pointin the second portion of the primary separation container.
 7. Theapparatus of claim 5 wherein said secondary separation container islocated generally below the downwardly inclined base of the primaryseparation container.
 8. The apparatus of claim 1 wherein the first weircomprises a catchment located behind the weir, the catchment beingoperable to receive the collected low specific gravity portion and todirect the collected low specific gravity portion to the secondaryseparation container.
 9. The apparatus of claim 8 further comprising aconduit extending between the catchment and the secondary separationcontainer.
 10. The apparatus of claim 8 wherein the first weir comprisesa weir having a J-shaped cross section.
 11. The apparatus of claim 1wherein the first weir comprises a serpentine weir.
 12. The apparatus ofclaim 1 wherein the first weir is positioned to collect the low specificgravity portion from a first area of the upper surface of theaccumulated feedstock in the primary separation container, and furthercomprising a second weir positioned proximate a second area of the uppersurface of the accumulated feedstock in the primary separationcontainer, the second weir being operable to permit feedstock in thesecond area from which a substantial portion of the low specific gravityportion has been collected to overflow to produce a second dischargestream at a second outlet.
 13. The apparatus of claim 12 furthercomprising a first launder box located to receive and accumulateoverflowing feedstock from the second weir, wherein the second outlet islocated at a low point in the first launder box.
 14. The apparatus ofclaim 12 wherein the second discharge stream comprises at least waterand a fine solids component.
 15. The apparatus of claim 1 wherein thefirst discharge stream comprises at least water and a coarse solidscomponent.
 16. The apparatus of claim 15 wherein the first dischargestream further comprises asphaltenes.
 17. The apparatus of claim 1further comprising a third outlet located in the secondary separationcontainer of the treatment vessel, the third outlet being located at alow point in the secondary separation container for producing a thirddischarge stream at the third outlet.
 18. The apparatus of claim 17wherein the third outlet comprises a water boot disposed below thesecondary separation container, the water boot having an outlet fordischarging the third discharge stream.
 19. The apparatus of claim 1wherein the product outlet comprises a third weir located in thesecondary separation container to cause the hydrocarbon products in theaccumulated low specific gravity portion to overflow to produce thehydrocarbon stream at the product outlet.
 20. The apparatus of claim 19wherein the product outlet comprises a second launder box located toreceive and accumulate the overflowing low specific gravity portion fromthe third weir and wherein the product outlet is located at a low pointin the second launder box.
 21. The apparatus of claim 1 wherein thefeedstock comprises an added diluent wherein the hydrocarbon productcomprises a hydrocarbon product portion and a diluent portion.
 22. Theapparatus of claim 21 wherein the added diluent comprises one of: aparaffinic diluent; or a naphthenic diluent.
 23. The apparatus of claim21 wherein the feedstock comprises at least about 60% diluent.
 24. Theapparatus of claim 1 wherein the treatment vessel comprises a pressurecontainment vessel and further comprising at least one gas outletoperably configured to discharge gaseous products released from thefeedstock during treatment.
 25. The apparatus of claim 24 furthercomprising a regulator regulating an operating pressure in the treatmentvessel.
 26. The apparatus of claim 25 wherein the regulator is operablyconfigured to regulate the operation pressure by: causing said at leastone gas outlet to be activated to release gaseous products when theoperating pressure in the treatment vessel is above a pre-determinedmaximum operating pressure; and introducing a supplementary pressurizinggas when the operating pressure in the treatment vessel falls below apre-determined minimum operating pressure.
 27. A process for treating aheavy hydrocarbon feedstock having a specific gravity differentialbetween components of the feedstock, the process comprising: receivingthe feedstock at an inlet of a treatment vessel; accumulating thefeedstock in a primary separation container in the treatment vessel tocause a low specific gravity portion of the feedstock to separate andrise to an upper surface of the accumulated feedstock; collecting with afirst weir the low specific gravity portion from the surface of theaccumulated feedstock in the primary separation container; directingsettling solids in the accumulated feedstock toward a first outlet ofthe treatment vessel to produce a first discharge stream at the firstoutlet; accumulating the collected low specific gravity portion in asecondary separation container in the treatment vessel to causehydrocarbon products to separate and rise to an upper surface of theaccumulated low specific gravity portion; and collecting the hydrocarbonproducts from the upper surface of the accumulated low specific gravityportion to produce a hydrocarbon product stream at a product outlet. 28.The process of claim 27 wherein receiving the feedstock comprisesreceiving a flow of feedstock at the inlet and causing the feedstock toflow along a feed manifold between the inlet and the primary separationcontainer for conditioning the feedstock flow to facilitate separationof the low specific gravity portion in the primary separation container.29. The process of claim 28 wherein conditioning the feedstock flowcomprises causing the feedstock to flow along a plurality of adjacentlylocated open channels extending between the inlet and the primaryseparation container, the open channels being operable to reduceturbulence intensity in the feedstock flow.
 30. The process of claim 28wherein causing the feedstock to flow along the feed manifold comprisescausing a feedstock flow into the primary separation container having aReynolds Number of about 20,000.
 31. The process of claim 27 whereindirecting settling solids in the accumulated feedstock toward the firstoutlet of the treatment vessel comprises causing the solids to bedirected along a downwardly inclined base of the primary separationcontainer toward the first outlet.
 32. The process of claim 31 whereinthe downwardly inclined base defines a first portion of the primaryseparation container and further comprising receiving the settlingsolids in a second portion of the primary separation container locatedto receive the solids from the downwardly inclined base, said firstoutlet being located at a low point in the second portion of the primaryseparation container.
 33. The process of claim 31 wherein accumulatingthe low specific gravity portion in the secondary separation containercomprises accumulating the low specific gravity portion in a secondaryseparation container located generally below the downwardly inclinedbase of the primary separation container.
 34. The process of claim 27wherein collecting the low specific gravity portion comprisesoverflowing the low specific gravity portion at the first weir disposedto receive an overflow stream from the primary separation container. 35.The process of claim 34 wherein collecting the low specific gravityportion comprises receiving the low specific gravity portion overflowingthe first weir in a catchment located behind the weir and directing thecollected low specific gravity portion to the secondary separationcontainer.
 36. The process of claim 35 wherein directing the collectedlow specific gravity portion to the secondary separation containercomprises causing the collected low specific gravity portion to flowthrough a conduit extending between the catchment and the secondaryseparation container.
 37. The process of claim 35 wherein receiving thelow specific gravity portion at the first weir comprises receiving thelow specific gravity portion at a weir having a J-shaped cross section.38. The process of claim 34 wherein receiving the low specific gravityportion at the first weir comprises receiving the low specific gravityportion at a serpentine weir.
 39. The process of claim 27 whereincollecting the low specific gravity portion comprises collecting the lowspecific gravity portion from a first area of the upper surface of theaccumulated feedstock and further comprising overflowing feedstock froma second area of the upper surface from which a substantial portion ofthe low specific gravity portion has been collected to produce a seconddischarge stream at a second outlet of the treatment vessel.
 40. Theprocess of claim 39 wherein overflowing feedstock from the second areaof the upper surface comprises causing the feedstock to overflow into afirst launder box, the second outlet being located at a low point in thefirst launder box.
 41. The process of claim 39 wherein producing thesecond discharge stream comprises producing a second discharge streamcomprising at least water and a fine solids component.
 42. The processof claim 27 wherein producing the first discharge stream comprisesproducing a discharge stream comprising at least water and a coarsesolids component.
 43. The process of claim 42 wherein producing thefirst discharge stream comprises producing a discharge stream comprisingasphaltenes.
 44. The process of claim 27 further comprising producing athird discharge stream at a third outlet of the treatment vessel, thethird outlet being located at a low point of the secondary separationcontainer.
 45. The process of claim 44 wherein producing the thirddischarge stream at the third outlet comprises causing aqueouscomponents to be collected in a water boot disposed below the secondaryseparation container, the water boot having an outlet for dischargingthe third discharge stream.
 46. The process of claim 27 whereincollecting the hydrocarbon products from the upper surface of theaccumulated low specific gravity portion comprises overflowing theaccumulated low specific gravity portion.
 47. The process of claim 46wherein overflowing the accumulated low specific gravity portioncomprises causing the hydrocarbon products in the low specific gravityportion of the feedstock to overflow into a second launder box, theproduct outlet being located at a low point in the second launder box.48. The process of claim 27 wherein the feedstock comprises an addeddiluent, and wherein collecting the hydrocarbon products comprisescollecting a hydrocarbon product portion and a diluent portion.
 49. Theprocess of claim 48 wherein the added diluent comprises one of: aparaffinic diluent; and a naphthenic diluent.
 50. The process of claim48 wherein the feedstock comprises at least about 60% diluent.
 51. Theprocess of claim 27 wherein the treatment vessel comprises a pressurecontainment vessel and further comprising causing gaseous productsreleased from the feedstock during treatment to be discharged from thetreatment vessel through at least one gas outlet.
 52. The process ofclaim 51 further comprising regulating an operating pressure in thetreatment vessel.
 53. The process of claim 52 wherein regulating theoperating pressure comprises: causing said at least one gas outlet to beactivated to release gaseous products when the operating pressure in thetreatment vessel is above a pre-determined maximum operating pressure;and introducing a supplementary pressurizing gas when the operatingpressure in the treatment vessel falls below a pre-determined minimumoperating pressure.
 54. An apparatus for treating a heavy hydrocarbonfeedstock having a specific gravity differential between components ofthe feedstock, the apparatus comprising: means for receiving thefeedstock at an inlet of a treatment vessel; means for accumulatingfeedstock in a primary separation container in the treatment vessel tocause a low specific gravity portion of the feedstock to separate andrise to an upper surface of the accumulated feedstock; means forcollecting the low specific gravity portion from the surface of theaccumulated feedstock in the primary separation container; means fordirecting settling solids in the accumulated feedstock toward a firstoutlet of the treatment vessel to produce a first discharge stream atthe first outlet; means for accumulating the collected low specificgravity portion in a secondary separation container in the treatmentvessel to cause hydrocarbon products to separate and rise to an uppersurface of the accumulated low specific gravity portion; and means forcollecting the hydrocarbon products from the upper surface of theaccumulated low specific gravity portion to produce a hydrocarbonproduct stream at a product outlet.